INPUT DETECTION SYSTEM
An input detection system includes a plurality of drive electrodes and a plurality of detection electrodes aligned in a detection region, an input device including an LC circuit, a first electrode coupled to one end side of the LC circuit, and a second electrode coupled to another end side of the LC circuit, the input support device being disposed on the detection region, and a control circuit configured to detect the input support device based on detection signals that are output from the detection electrodes.
This application claims the benefit of priority from Japanese Patent Application No. 2021-005964 filed on Jan. 18, 2021, the entire contents of which are incorporated herein by reference.
BACKGROUND 1. Technical FieldThe present disclosure relates to an input detection system.
2. Description of the Related ArtJapanese Patent Nos. 6342105 and 6532631 describe an input support device (referred to as an operation knob or a knob in Japanese Patent Nos. 6342105 and 6532631) that is placed on a touch panel configured to detect change in electrostatic capacitance or change in a contact region and supports input operations through the touch panel. As a method for detecting the input support device, a method with which the input support device is detected using resonance of a resonance circuit provided in the input support device has been known. An input detection system using the above-mentioned input support device can detect operation states of the input support device based on pieces of information such as a rotation angle and a shape of the input support device in addition to position information of the input support device.
The input detection system is required to detect various pieces of information of the input support device with high accuracy.
SUMMARYAn input detection system includes a plurality of drive electrodes and a plurality of detection electrodes aligned in a detection region, an input device including an LC circuit, a first electrode coupled to one end side of the LC circuit, and a second electrode coupled to another end side of the LC circuit, the input support device being disposed on the detection region, and a control circuit configured to detect the input support device based on detection signals that are output from the detection electrodes. Each of the first electrode and the second electrode of the input device faces some of the drive electrodes and detection electrodes, a reference potential is supplied to the drive electrode corresponding to one of the first electrode and the second electrode, a drive signal is supplied to the drive electrode corresponding to the other of the first electrode and the second electrode, each of the first electrode and the second electrode forms capacitance with the facing detection electrode based on the reference potential or the drive signal, and the detection electrodes form capacitances with the first electrode and the second electrode of the input support device and the adjacent drive electrode and output the detection signals that are generated based on the capacitances to the control circuit, and the control circuit forms two-dimensional distribution of a plurality of signal values corresponding to the detection region based on the detection signals that are output from the detection electrodes and detects, from the two-dimensional distribution, a plurality of positive-polarity regions formed by a plurality of positive-polarity signal values of equal to or larger than a predetermined first threshold and a plurality of negative-polarity regions formed by a plurality of negative-polarity signal values of equal to or smaller than a predetermined second threshold.
Aspects for carrying out the present disclosure (embodiments) will be described in detail with reference to the drawings. Contents described in the following embodiments do not limit the present disclosure. Components described below include those that can be easily assumed by those skilled in the art and substantially the same components. Furthermore, the components described below can be appropriately combined. What is disclosed herein is merely an example, and appropriate modifications within the gist of the disclosure of which those skilled in the art can easily think are naturally encompassed in the scope of the present disclosure. In the drawings, widths, thicknesses, shapes, and the like of the components can be schematically illustrated in comparison with actual aspects for more clear explanation. They are however merely examples and do not limit interpretation of the present disclosure. In the present disclosure and the drawings, the same reference numerals denote components similar to those described before with reference to the drawing that has been already referred, and detail explanation thereof can be appropriately omitted.
In the present specification and the scope of the invention, when an aspect in which another structure is arranged above a certain structure is represented, simple expression “above” includes both of the case in which another structure is arranged just above the certain structure and the case in which another structure is arranged above the certain structure with still another structure interposed therebetween unless otherwise specified.
First EmbodimentOne direction of a plane (upper surface 111a) of the display device 2 is a first direction Dx, and a direction orthogonal to the first direction Dx is a second direction Dy. The second direction Dy is not limited to be orthogonal to the first direction Dx and may intersect with the first direction Dx at an angle other than 90°. A third direction Dz orthogonal to the first direction Dx and the second direction Dy corresponds to the thickness direction of an array substrate SUB1.
As illustrated in
The array substrate SUB1 is a drive circuit substrate for driving a plurality of pixels PX. The array substrate SUB1 includes a first substrate 10 as a base body. The array substrate SUB1 includes switching elements Tr and various wiring lines such as scan lines GL and pixel signal lines SL (refer to
The length of the array substrate SUB1 in the second direction Dy is larger than the length of the counter substrate SUB2 in the second direction Dy. As illustrated in
As illustrated in
The display region DA is a region for displaying an image and is a region in which the pixels PX are provided. The peripheral region BE indicates a region on the inner side of the outer circumference of the array substrate SUB1 and on the outer side of the display region DA. The peripheral region BE may have a frame shape surrounding the display region DA, and in this case, the peripheral region BE can also be referred to as a frame region.
As illustrated in
A wiring substrate 115 is coupled to the counter substrate SUB2. A detection IC 51 is mounted on the wiring substrate 115. The detection IC 51 includes a detection circuit 55 (refer to
Each of the wiring substrate 114 and the wiring substrate 115 is configured by, for example, flexible printed circuits (FPC). The wiring substrate 114 is coupled to a plurality of terminals of the first substrate 10. The wiring substrate 115 is coupled to a plurality of terminals of the second substrate 20.
As illustrated in
As illustrated in
The array substrate SUB1 faces the illumination device IL, and the counter substrate SUB2 is located on the display surface side. The illumination device IL emits light toward the array substrate SUB1. For example, a side light-type backlight or a direct-type backlight can be applied to the illumination device IL. Although various aspects can be applied to the illumination device IL, explanation of the detail configurations thereof is omitted.
An optical element including the first polarizing plate PL1 faces the first substrate 10. To be more specific, the first polarizing plate PL1 is arranged on the outer surface of the first substrate 10 or on the surface thereof facing the illumination device IL. An optical element including the second polarizing plate PL2 faces the second substrate 20. To be more specific, the second polarizing plate PL2 is arranged on the outer surface of the second substrate 20 or on the surface thereof on an observation position side. A first polarization axis of the first polarizing plate PL1 and a second polarization axis of the second polarizing plate PL2 have a crossed Nicol positional relation in an X-Y plane, for example. The optical elements including the first polarizing plate PL1 and the second polarizing plate PL2 may include another optical function element such as a phase difference plate.
The array substrate SUB1 includes insulating films 11, 12, 13, 14, and 15, the pixel signal lines SL, pixel electrodes PE, the drive electrodes Tx (common electrodes CE), a first orientation film AL1, and the like on the side of the first substrate 10 that faces the counter substrate SUB2.
In the present specification, the direction toward the second substrate 20 from the first substrate 10 in the direction perpendicular to the first substrate 10 is an “upper-side” or simply an “above”. The direction toward the first substrate 10 from the second substrate 20 is a “lower-side” or simply a “downward”. The expression “plan view” indicates a positional relation when seen from the direction perpendicular to the first substrate 10.
The insulating film 11 is provided above the first substrate 10. The insulating films 11, 12, and 13, and the insulating film 15 are, for example, inorganic insulating films made of an inorganic material having a light transmitting property, such as silicon oxide and silicon nitride.
The insulating film 12 is provided above the insulating film 11. The insulating film 13 is provided above the insulating film 12. The pixel signal lines SL are provided above the insulating film 13. The insulating film 14 is provided above the insulating film 13 and covers the pixel signal lines SL. The insulating film 14 is made of a resin material having a light transmitting property and has a film thickness that is larger than that of the other insulating films made of the inorganic material. Although not illustrated in
The drive electrodes Tx are provided above the insulating film 14. The drive electrodes Tx are provided in the display region DA and are divided into a plurality of parts by slits SLT. Alternatively, a plurality of in-electrode slits (not illustrated) may be provided in the drive electrodes Tx. The drive electrodes Tx are covered by the insulating film 15. The drive electrodes Tx serve as the drive electrodes Tx for touch detection and the common electrodes CE in display.
The pixel electrodes PE are provided above the insulating film 15 and face the drive electrodes Tx with the insulating film 15 interposed therebetween. The pixel electrodes PE and the drive electrodes Tx are made of, for example, a conductive material having a light transmitting property, such as indium tin oxide (ITO) and indium zinc oxide (IZO). The first orientation film AL1 covers the pixel electrodes PE and the insulating film 15.
The counter substrate SUB2 includes the light shielding layer BM, color filters CFR, CFG, and CFB, an overcoat layer OC, a second orientation film AL2, and the like on the side of the second substrate 20 that faces the array substrate SUB1. The counter substrate SUB2 includes the detection electrodes Rx and the second polarizing plate PL2 on the side of the second substrate 20 that is opposite to the array substrate SUB1.
The light shielding layer BM is located on the side of the second substrate 20 that face the array substrate SUB1 in the display region DA. The light shielding layer BM defines openings that respectively face the pixel electrodes PE. The pixel electrodes PE are partitioned for the respective openings of the pixels PX. The light shielding layer BM is made of a resin material in black color or a metal material having a light shielding property.
The color filters CFR, CFG, and CFB are located on the side of the second substrate 20 that faces the array substrate SUB1, and end portions thereof overlap with the light shielding layer BM. As an example, the color filters CFR, CFG, and CFB are made of a resin material colored with red, green, and blue, respectively.
The overcoat layer OC covers the color filters CFR, CFG, and CFB. The overcoat layer OC is made of a resin material having a light transmitting property. The second orientation film AL2 covers the overcoat layer OC. The first orientation film AL1 and the second orientation film AL2 are made of, for example, a material exhibiting horizontal orientation performance.
The detection electrodes Rx are provided above the second substrate 20. The detection electrodes Rx are metal wiring made of a conductive material, for example. Alternatively, the detection electrodes Rx may be made of a conductive material having a light transmitting property, such as ITO.
The array substrate SUB1 and the counter substrate SUB2 are arranged such that the first orientation film AL1 and the second orientation film AL2 face each other. The liquid crystal layer LC is enclosed into between the first orientation film AL1 and the second orientation film AL2. The liquid crystal layer LC is made of a negative liquid crystal material having a negative dielectric anisotropy or a positive liquid crystal material having a positive dielectric anisotropy.
For example, when the liquid crystal layer LC is made of the negative liquid crystal material and a state in which no voltage is applied to the liquid crystal layer LC is established, liquid crystal molecules LM are initially oriented in such a direction that long axes thereof are along the first direction Dx in the X-Y plane. On the other hand, in a state in which a voltage is applied to the liquid crystal layer LC, that is, in an ON state in which an electric field is formed between the pixel electrodes PE and the drive electrodes Tx, the liquid crystal molecules LM receive influences of the electric field and orientation states thereof are changed. In the ON state, a polarization state of incident linearly polarized light is changed in accordance with the orientation states of the liquid crystal molecules LM when it passes through the liquid crystal layer LC.
Each pixel PX includes the sub pixels SPX. Each sub pixel SPX includes the switching element Tr and capacitance of the liquid crystal layer LC. The switching element Tr is formed by a thin film transistor and, in this example, is formed by an n-channel metal oxide semiconductor (MOS)-type TFT. The insulating film 15 is provided between the pixel electrodes PE and the drive electrodes Tx illustrated in
Color regions colored with three colors of red (R), green (G), and blue (B), for example, are periodically arrayed as the color filters CFR, CFG, and CFB. The color regions of the three colors of R, G, and B as one set are made to respectively correspond to the sub pixels SPX. A set of sub pixels SPX corresponding to the color regions of the three colors configures the pixel PX. The color filters may include color regions of equal to or more than four colors. In this case, the pixel PX may include equal to or more than four sub pixels SPX.
Each of the drive electrodes Tx extends in the second direction Dy and is aligned in the first direction Dx. The drive electrodes Tx are coupled to the display IC 50 through respective coupling wiring lines 53A. Each of the detection electrodes Rx extends in the first direction DX and is aligned in the second direction Dy. The detection electrodes Rx are coupled to the detection IC 51 through coupling wiring lines 53B. The drive electrodes Tx and the detection electrodes Rx are provided so as to intersect with each other in a plan view. An electrostatic capacitance is formed in each of intersecting portions of the drive electrodes Tx and the detection electrodes Rx. The detection IC 51 can detect the detection target based on the detection signals Vdet that are output in accordance with change in the mutual electrostatic capacitances between the drive electrodes Tx and the detection electrodes Rx.
Although
The drive electrodes Tx serve as the common electrodes CE for forming an electric field between the drive electrodes Tx and the pixel electrodes PE in display and as the drive electrodes Tx for detecting the detection target such as the finger Fg and the input support device 3 in touch detection. To be specific, the display IC 50 supplies a display drive signal VCOM to the drive electrodes Tx in display. The display IC 50 includes at least a drive signal supply circuit 56. The drive signal supply circuit 56 supplies a detection drive signal VD to the drive electrodes Tx in order. Details of driving of the drive electrodes Tx will be described later.
Next, a method for detecting the input support device 3 will be described with reference to
To be specific, the first electrode 31 has a circular shape in a plan view. The second electrode 32 has a curved shape curved in a circular arc form (C-shaped form) along the inner circumference of the housing 30 (refer to
Alternatively, the total area of the drive electrodes Tx overlapping with the first electrode 31 is different from the total area of the drive electrodes Tx overlapping with the second electrode 32. In the example illustrated in
The capacitor 33 configuring the LC circuit 35 is coupled between the first electrode 31 and one end side of the second electrode 32. The inductor 34 is coupled between the first electrode 31 and the other end side of the second electrode 32.
The input support device 3 is arranged so as to overlap with the drive electrodes Tx and the detection electrodes Rx. A capacitance C1 is formed between the first electrode 31 and one drive electrode Tx (the drive electrode Tx on the left side in
A capacitance C3 is formed between the second electrode 32 and the detection electrode Rx facing the second electrode 32. Each of the detection electrodes Rx (the detection electrode Rx on the right side in
The detection circuit 55 is a signal processing circuit provided in the detection IC 51 and is a circuit that receives the detection signals Vdet (refer to
The display IC 50 (refer to
The first detection period TP1 is arranged between the first display period DP1 and the second display period DP2. The detection target such as the finger Fg is detected in the first detection period TP1. To be specific, the drive signal supply circuit 56 (refer to
The detection IC 51 performs signal processing on the detection signals Vdet1 output from the detection electrodes Rx. The detection IC 51 calculates first frame data (Frame_data1) formed by a plurality of signal values based on the detection signals Vdet1 for one frame. The detection IC 51 can detect presence of the detection target such as the finger Fg and positional information thereof by comparing the signal values on which the calculation processing has been performed with a predetermined threshold. Touch detection for one frame, that is, the overall detection region (display region DA) is performed in one first detection period TP1.
The second detection period TP2 is arranged between the second display period DP2 and the first display period DP1 in the subsequent frame period F. The input support device 3 and the detection target such as the finger Fg are detected in the second detection period TP2. To be specific, the drive signal supply circuit 56 (refer to
The detection IC 51 performs signal processing on the detection signals Vdet2 output from the detection electrodes Rx. The detection IC 51 calculates second frame data (Frame_data2) formed by a plurality of signal values based on the detection signals Vdet2 for one frame. The detection IC 51 can detect information related to a position and a rotation angle of the input support device 3 by comparing the signal values on which the calculation processing has been performed with a predetermined threshold. The detection target such as the finger Fg can be detected by utilizing the second frame data used in the detection of the input support device 3 in the second detection period TP2. That is to say, the detection IC 51 can detect the position or the like of the input support device 3 and the finger Fg by utilizing the change in the mutual electrostatic capacitances and the resonance of the LC circuit 35 included in the input support device 3. Detection for one frame, that is, the overall detection region (display region DA) is performed in one second detection period TP2. That is to say, a detection report rate TR of the detection target such as the finger Fg has the length of about half of the frame period F.
The timing waveform chart illustrated in
Next, a method for detecting the input support device 3 in the second detection period TP2 will be described with reference to
As illustrated in
The detection electrode Rx outputs the detection signals Vdet2 based on the mutual electrostatic capacitance Cm. To be specific, one drive electrode Tx (the drive electrode Tx on the left side in
The detection signal amplifier 61 of the detection circuit 55 amplifies the detection signals Vdet2 supplied from the detection electrode Rx. A reference voltage having a fixed potential is input to a non-inverting input portion of the detection signal amplifier 61, and the detection electrode Rx is coupled to an inverting input terminal. A signal that is the same as that to one drive electrode Tx is input as the reference voltage in the present embodiment. The detection circuit 55 can reset charges of the capacitive element 62 by turning the reset switch 63 ON.
The second detection drive signal VD2 has the same frequency as the resonant frequency of the LC circuit 35. In the present embodiment, the switching operation of the switch element 54B is performed based on the resonant frequency to form the second detection drive signal VD2 having the resonant frequency. The second electrode 32 overlapping with the other drive electrode Tx is also driven at the resonant frequency, so that resonance of the LC circuit 35 is generated. With this configuration, the amplitudes of the detection signals Vdet2 are thereby increased as the first period P1 and the second period P2 are repeated in the detection period. As illustrated in
With the resonance of the LC circuit 35, the waveform that is generated in the first electrode 31 varies from the waveform that is generated in the second electrode 32 such that the polarities of the first electrode 31 and the second electrode 32 are changed so as to invert from each other. To be specific, the potential of the first electrode 31 varies to be increased and the second electrode 32 varies to be decreased in each first period P1. The potential of the first electrode 31 varies to be decreased and the potential of the second electrode 32 varies to be increased in each second period P2.
Accordingly, the detection signals Vdet2 that are output from the detection electrode Rx overlapping with the first electrode 31 and the output signal Vo (not illustrated) based on the detection signals Vdet2, and the detection signals Vdet2 that are output from the detection electrode Rx overlapping with the second electrode 32 and the output signal Vo (refer to
On the other hand, when the detection target such as the finger Fg different from the input support device 3 comes into contact with or close to the upper surface 111a (refer to
The calculation circuit 51A outputs, to a host IC 101, the information related to the finger Fg and the information related to the input support device 3 that have been provided by the calculation. The host IC 101 is a circuit configured to control the display device 2. The host IC 101 outputs, to the display device 2, an instruction to execute an operation in accordance with an input operation based on the information related to the finger Fg and the information related to the input support device 3. The detection IC 51 is controlled to operate in synchronization with the display IC 50 (refer to
The detection IC 51 is not limited to the configuration in which the it calculates the information related to the finger Fg and the information related to the input support device 3, and the host IC 101 as an external circuit may receive the pieces of frame data from the detection IC 51 and calculate the information related to the finger Fg and the information related to the input support device 3.
Next, a specific method for detecting various pieces of information (position and rotation angle) of the input support device 3 will be described.
As illustrated in
The detection IC 51 performs the above-mentioned signal processing with the detection circuit 55 based on the detection signals Vdet1 for one frame. The detection IC 51 detects the first frame data based on the signal values of the output signals Vo for one frame that have been provided by the signal processing (step ST12).
The detection IC 51 calculates a baseline based on the first frame data (step ST13) and updates an existing baseline. The calculation of the baseline may be omitted, and it is sufficient that the calculation of the baseline is executed at predetermined timing such as power-on time and recovery time from a sleep mode.
Subsequently, the detection IC 51 performs signal processing on the first frame data to calculate a first detection value (touch detection) (step ST14). The first detection value is, for example, the information related to the detection target such as the finger Fg. The first detection value is calculated by, for example, calculating difference between the first frame data and the baseline or calculating comparison between the first frame data and the predetermined threshold.
Then, the detection IC 51 determines presence of touch of the detection target such as the finger Fg based on the first detection value (step ST15) and calculates a touch position of the detection target such as the finger Fg when the detection target such as the finger Fg is detected.
Thereafter, the drive signal supply circuit 56 (refer to
The detection IC 51 performs the above-mentioned signal processing with the detection circuit 55 based on the detection signals Vdet2 for one frame. The detection IC 51 detects the second frame data based on the signal values of the output signals Vo for one frame that have been provided by the signal processing in the detection circuit 55 (step ST17).
Subsequently, the detection IC 51 performs signal processing on the second frame data to calculate a second detection value (input support device) (step ST18). The second detection value is, for example, various pieces of information of the input support device 3, such as the position and the rotation angle of the input support device 3. The above-mentioned first detection value (touch detection) is calculated utilizing the second frame data used in the detection of the input support device 3 at step ST18.
A specific example of the calculation of the second detection value will be described with reference to
First, as illustrated in
To be specific, as illustrated in
As illustrated in
The second detection drive signal VD2 is supplied to the drive electrode Tx3 overlapping with the first electrode 31 in the period PA3. The drive electrode Tx3 overlaps also with the second electrode 32, and the second electrode 32 is larger than the first electrode 31 and overlaps also with the other drive electrodes Tx1, Tx2, Tx4, and Tx5 coupled to the reference potential. As a result, the capacitance on the second electrode 32 side is relatively smaller than the capacitance on the first electrode 31 side. Accordingly, the positive-polarity detection signals Vdet2 are output from the detection electrodes Rx4 and Rx5 overlapping with the first electrode 31 and the negative-polarity detection signals Vdet2 are output from the detection electrodes Rx1, Rx2, and Rx3 not overlapping with the second electrode 32 in the period PA3.
The second detection signal VD2 is supplied to the drive electrodes Tx4 and Tx5 overlapping with the second electrode 32 in the respective periods PA4 and PA5. The drive electrode Tx3 overlapping with the first electrode 31 is coupled to the reference potential. The positive-polarity detection signals Vdet2 are output from the detection electrodes Rx1, Rx2, and Rx3 overlapping with the second electrode 32 and the negative-polarity detection signals Vdet2 are output from the detection electrodes Rx4 and Rx5 not overlapping with the second electrode 32 in the periods PA4 and PA5.
As illustrated in
As illustrated in
A signal value KSm1 is a signal value of the negative-polarity detection signal Vdet2 (output signal Vo) and is a signal value of larger than a threshold THc, in other words, a signal value having an absolute value smaller than that of the threshold THc. A signal value KSm2 is a signal value of the negative-polarity detection signal Vdet2 (output signal Vo) and is a signal value of equal to or smaller than the threshold THc, in other words, a signal value having an absolute value equal to or larger than that of the threshold THc.
In the following explanation, when the positive-polarity signal values KSp1, KSp2, and KSp3 need not to be distinguished from each other for explanation, they can be referred to as signal values KSp simply. When the negative-polarity signal values KSm1 and KSm2 need not to be distinguished from each other for explanation, they can be referred to as signal values KSm simply.
As illustrated in
The positive-polarity signal value KSp1 or KSp2 is provided at each of positions SP21, SP22, and SP23 as regions overlapping with the drive electrode Tx2 and the detection electrodes Rx1, Rx2, and Rx3 in the period PA2. The negative-polarity signal value KSm1 is provided at each of positions SP24 and SP25 as regions overlapping with the drive electrode Tx2 and the detection electrodes Rx4 and Rx5.
The negative-polarity signal value KSm1 or KSm2 is provided at each of positions SP31, SP32, and SP33 as regions overlapping with the drive electrode Tx3 and the detection electrodes Rx1, Rx2, and Rx3 in the period PA3. The positive-polarity signal value KSp3 is provided at each of positions SP34 and SP35 as regions overlapping with the drive electrode Tx3 and the detection electrodes Rx4 and Rx5.
The positive-polarity signal value KSp1 or KSp2 is provided at each of positions SP41, SP42, and SP43 as regions overlapping with the drive electrode Tx4 and the detection electrodes Rx1, Rx2, and Rx3 in the period PA4. The negative-polarity signal value KSm1 is provided at each of positions SP44 and SP45 as regions overlapping with the drive electrode Tx4 and the detection electrodes Rx4 and Rx5.
The positive-polarity signal value KSp1 or KSp2 is provided at each of positions SP51, SP52, and SP53 as regions overlapping with the drive electrode Tx5 and the detection electrodes Rx1, Rx2, and Rx3 in the period PA5. The negative-polarity signal value KSm1 is provided at each of positions SP54 and SP55 as regions overlapping with the drive electrode Tx5 and the detection electrodes Rx4 and Rx5.
The input detection system 1 can thus detect the regions formed by the positive-polarity signal values KSp and the regions formed by the negative-polarity signal values KSm in the two-dimensional distribution of the signal values KSp and KSm of the detection signals Vdet2 (output signals Vo) by the resonance of the LC circuit 35 of the input support device 3. On the other hand, the detection target such as the finger Fg causes no resonance of the LC circuit 35, so that only signal values having one polarity (for example, the positive-polarity signal values KSp) are provided. The detection IC 51 can determine that the input support device 3 is arranged on the display region DA when the regions formed by the positive-polarity signal values KSp and the regions formed by the negative-polarity signal values KSm are detected at step ST21 illustrated in
In the example illustrated in
With reference to
Hereinafter, an example of a method for detecting the peak positions of the signal values KSp and KSm and an electrode angle θe will be described with reference to
A rotation angle θk of the input support device 3 is an angle formed by a virtual line passing through the center (rotating axis AX) of the input support device 3 and parallel with the first direction Dx and a virtual line connecting the center (rotating axis AX) of the input support device 3 and the center of the first electrode 31. For example, the rotation angle θk of the input support device 3 illustrated in
As illustrated in
In the following explanation, when the first positive-polarity region PP1, the second positive-polarity region PP2, and the third positive-polarity region PP3 need not to be distinguished from each other for explanation, they can be referred to as positive-polarity regions PP simply. When the first negative-polarity region PM1, the second negative-polarity region PM2, and the third negative-polarity region PM3 need not to be distinguished from each other for explanation, they can be referred to as negative-polarity regions PM simply.
The positive-polarity regions PP are peak regions formed by the positive-polarity signal values KSp of equal to or larger than a predetermined threshold. The negative-polarity regions PM are peak regions formed by the negative-polarity signal values KSm of equal to or smaller than a predetermined threshold.
As illustrated in
The positive-polarity regions PP and the negative-polarity regions PM having different polarities are arranged so as to be adjacent to each other in the first direction Dx or the second direction Dy. The positive-polarity regions PP having the same polarity are arranged so as to be adjacent to each other diagonally (in the oblique direction). The negative-polarity regions PM having the same polarity are arranged so as to be adjacent to each other diagonally (in the oblique direction).
With reference to
When the number of peaks of the signal values KSp and KSm is six, the detection IC 51 calculates the electrode angle θe using two peaks including a maximum peak and a peak having the same polarity as that of the maximum peak and having a second largest value (step ST24). In the example illustrated in
As illustrated in
In the determination of the presence of the input support device 3 at step ST21 illustrated in
d2<dp<d1 (1)
The peak-to-peak distance dp is a distance between the gravity center PG of the positive-polarity region PP and the gravity center PG of the negative-polarity region PM, which are adjacent to each other, and is the shortest distance between the gravity centers PG. d1 and d2 are parameters that are determined by a distance between the first electrode 31 and the second electrode 32 included in the input support device 3 and the shapes of the electrodes.
Although, in the above-mentioned example, the case where the number of positive-polarity regions PP and the negative-polarity regions PM are six is described, the number thereof is not however limited thereto. Distribution of the signal values KSp and KSm is detected to be different and the number and positions (gravity centers PG) of the positive-polarity regions PP and the negative-polarity regions PM are also different in accordance with the rotation angle θk of the input support device 3.
As illustrated in
As illustrated in
The first positive-polarity region PP1 is a region overlapping with the first electrode 31. The second positive-polarity region PP2 is a region overlapping with the second electrode 32 and is a region in the vicinity of the center of the second electrode 32 in the extension direction. The second positive-polarity region PP2 is located diagonally to the first positive-polarity region PP1.
The first negative-polarity region PM1 and the second negative-polarity region PM2 are regions in the vicinity of end portions of the second electrode 32 in the extension direction. The first negative-polarity region PM1 is located diagonally to the second negative-polarity region PM2. The first negative-polarity region PM1 is arranged so as to be adjacent to the first positive-polarity region PP1 in the first direction Dx and is arranged so as to be adjacent to the second positive-polarity region PP2 in the second direction Dy. The second negative-polarity region PM2 is arranged so as to be adjacent to the first positive-polarity region PP1 in the second direction Dy and is arranged so as to be adjacent to the second positive-polarity region PP2 in the first direction Dx.
Also when the rotation angle θk is 135°, the positive-polarity regions PP and the negative-polarity regions PM having different polarities are arranged so as to be adjacent to each other in the first direction Dx or the second direction Dy. The positive-polarity regions PP having the same polarity are arranged so as to be adjacent to each other diagonally (in the oblique direction). The negative-polarity regions PM having the same polarity are arranged so as to be adjacent to each other diagonally (in the oblique direction).
The detection IC 51 detects the number of peaks of the signal values KSp and KSm in the two-dimensional distribution of the signal values KSp and KSm of the detection signals Vdet2 (output signals Vo) at step ST23 illustrated in
When the number of peaks is four, the detection IC 51 calculates the electrode angle θe using two peaks including a maximum peak and a peak having the same polarity as that of the maximum peak (step ST25 in
Then, with reference to
The detection IC 51 calculates the rotation angle θk of the input support device 3 by applying information of the electrode angle θe calculated at step ST24 or step ST25 to the conversion table illustrated in
The detection IC 51 is not limited to the method using the conversion table and may calculate the rotation angle θk of the input support device 3 by another method, for example, by using an approximate expression.
Then, the detection IC 51 calculates a position of the rotating axis AX based on the rotation angle θk of the input support device 3 (step ST27). To be specific, the detection IC 51 calculates the position of the first electrode 31 based on the gravity center PG of the first positive-polarity region PP1 provided at step ST22 as described above. The position of the rotating axis AX, that is, the center position of the input support device 3 can be calculated based on the rotation angle θk of the input support device 3 and a radius d (refer to
Also at step ST27, the detection IC 51 may calculate the position of the rotating axis AX using a conversion table provided by actual measurement or may calculate the position of the rotating axis AX by using an approximate expression similarly to
The input detection system 1 can detect the position of the rotating axis AX of the input support device 3 and the rotation angle θk thereof with high accuracy with the above-mentioned methods. The flowcharts illustrated in
Subsequently, with reference to
As described above, the input detection system 1 of the present embodiment includes the drive electrodes Tx and the detection electrodes Rx arrayed in the display region DA (detection region), the input support device 3 including the LC circuit 35, the first electrode 31 coupled to one end side of the LC circuit 35, and the second electrode 32 coupled to the other end side of the LC circuit 35, and the detection IC 51 (control circuit) configured to detect the input support device 3 based on the detection signals Vdet2 that are output from the detection electrodes Rx. The reference potential is supplied to the drive electrode Tx corresponding to one of the first electrode 31 and the second electrode 32, the second detection drive signal VD2 is supplied to the drive electrode Tx corresponding to the other of the first electrode 31 and the second electrode 32, the control circuit detects the positive-polarity regions PP formed by the positive-polarity signal values KSp of equal to or larger than a predetermined first threshold and the negative-polarity regions PM formed by the negative-polarity signal values KSm of equal to or smaller than a predetermined second threshold in the two-dimensional distribution of the signal values KSp and KSm based on the detection signals Vdet2.
First Modification
In the input detection system 1 according to the first modification, an example in which the electrode angle θe is calculated using three peaks at step ST24 (refer to FIG. 12) as described above will be described. In
As illustrated in
As illustrated in
An arrangement relation among the three positive-polarity regions PP and the three negative-polarity regions PM is similar to that in the above-mentioned first embodiment. That is to say, the positive-polarity regions PP and the negative-polarity regions PM having different polarities are arranged so as to be adjacent to each other in the first direction Dx or the second direction Dy. The positive-polarity regions PP having the same polarity are arranged so as to be adjacent to each other diagonally (in the oblique direction), and the negative-polarity regions PM having the same polarity are arranged so as to be adjacent to each other diagonally (in the oblique direction). The gravity center positions of the three positive-polarity regions PP and the three negative-polarity regions PM, and the respective peak signal values thereof are however different from those in the above-mentioned first embodiment (refer to
As illustrated in
The detection IC 51 calculates respective peak signal values PLV1, PLV2, and PLV3 of the first positive-polarity region PP1, the second positive-polarity region PP2, and the third positive-polarity region PP3 that are used for calculation of the electrode angle θe. The peak signal values PLV1, PLV2, and PLV3 are signal values KSp indicating maximum values among the positive-polarity signal values KSp forming the respective positive-polarity regions PP.
In the first modification, the detection IC 51 weights the first electrode angle θe1 and the second electrode angle θe2 using coefficients calculated with the peak signal values PLV1, PLV2, and PLV3 to thereby calculate the electrode angle θe. To be specific, the detection IC 51 calculates the electrode angle θe based on the following equation (2).
θe=(θe1×(PLV2/PLV3)+ee2×(PLV3/PLV2))/2 (2)
As described above, the detection IC 51 multiplies each of the first electrode angle θe1 and the second electrode angle θe2 calculated with the three peaks (the first positive-polarity region PP1, the second positive-polarity region PP2, and the third positive-polarity region PP3) by a ratio of the peak signal values PLV2 to PLV3 as a coefficient. The detection IC 51 can thereby calculate the electrode angle θe with high accuracy. That is to say, when a difference between the peak signal value PLV2 and the peak signal value PLV3 is small, an error between the electrode angle θe when the first positive-polarity region PP1 and the second positive-polarity region PP2 are selected as two peaks and the electrode angle θe when the first positive-polarity region PP1 and the third positive-polarity region PP3 are selected as two peaks can be reduced at step ST24 as described above.
In the first modification, when the rotation angle θk of the input support device 3 is calculated based on the electrode angle θe calculated using the equation (2), the detection IC 51 can use not the conversion table illustrated in
Second Modification
To be specific, as illustrated in
PPi(x,y)=(PP2(x,y)×(PLV2/PLV3)+PP3(x,y)×(PLV3/PLV2))/2 (3)
It should be noted that PPi(x, y), PP2(x, y), and PP3(x, y) are positions of the intermediate peak region PPi, the second positive-polarity region PP2, and the third positive-polarity region PP3 respectively on an xy coordinate system.
As illustrated in
The detection IC 51 detects, as the electrode angle θe, an angle formed by a virtual line passing through the gravity center PG of the first positive-polarity region PP1 and parallel with the first direction Dx and a virtual line connecting the gravity center PG of the first positive-polarity region PP1 and the gravity center PG of the intermediate peak region PPi.
When the rotation angle θk of the input support device 3 is calculated based on the electrode angle θe calculated in the second modification, the detection IC 51 can use not the conversion table illustrated in
Third Modification
As illustrated in
When both of the peak signal values PLV2 and PLV3 are equal to or larger than the threshold THd, the detection IC 51 calculates the electrode angle θe by any of the methods in the first modification and the second modification as described above.
When difference between the peak signal value PLV2 and the peak signal value PLV3 is small, difference between the coefficient (PLV2/PLV3) and the coefficient (PLV3/PLV2) used in the above-mentioned equation (2) or equation (3) is small. In the third modification, the detection IC 51 calculates difference between the peak signal value PLV2 and the threshold THd, and difference between the peak signal value PLV3 and the threshold THd. A correction signal value PLV2A provided by the differences is PLV2A=PLV2−THd. A correction signal value PLV3A is PLV3A=PLV3−THd.
The detection IC 51 calculates a new coefficient (PLV2A/PLV3A) and a new coefficient (PLV3A/PLV2A) using the correction signal value PLV2A and the correction signal value PLV3A. The detection IC 51 substitutes the coefficient (PLV2A/PLV3A) and the coefficient (PLV3A/PLV2A) in place of the coefficient (PLV2/PLV3) and the coefficient (PLV3/PLV2) in the equation (2) or the equation (3). In the third modification, difference between the coefficients of the peak signal values PLV2 and PLV3 can thus be increased, thereby reliably performing correction (weighting) in accordance with the peak signal values PLV2 and PLV3 in the equation (2) or the equation (3).
Fourth Modification
As illustrated in
As illustrated in
Two positive-polarity regions PP(32) including the regions L3 and L4 are detected in a rotation region R3 in which the rotation angle θk is around θk=90° (when the first electrode 31 is at a position corresponding to positive-polarity regions PP(31-2)).
Similarly, two positive-polarity regions PP(32) including the regions L1 and L4 are detected in a rotation region R5 in which the rotation angle θk is around θk=180°. Two positive-polarity regions PP(32) including the regions L1 and L2 are detected in a rotation region R7 in which the rotation angle θk is around θk=270°.
One positive-polarity region PP(32) of the region L3 is detected in a rotation region R2 illustrated in
The detection IC 51 can calculate the rotation angle θk using the conversion table illustrated in
Fifth Modification
As illustrated in
In
Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited by these embodiments. Contents disclosed in the embodiments are merely examples, and various modifications can be made in a scope without departing from the gist of the present disclosure. Appropriate modifications in a scope without departing from the gist of the present disclosure naturally belong to the technical scope of the present disclosure. At least one of various omission, replacement, and modification of the components can be performed in a scope without departing from the gist of the embodiments and modifications described above.
Claims
1. An input detection system comprising:
- a plurality of drive electrodes and a plurality of detection electrodes aligned in a detection region;
- an input device including an LC circuit, a first electrode coupled to one end side of the LC circuit, and a second electrode coupled to another end side of the LC circuit, the input support device being disposed on the detection region; and
- a control circuit configured to detect the input support device based on detection signals that are output from the detection electrodes, wherein
- each of the first electrode and the second electrode of the input device faces some of the drive electrodes and detection electrodes, a reference potential is supplied to the drive electrode corresponding to one of the first electrode and the second electrode, a drive signal is supplied to the drive electrode corresponding to the other of the first electrode and the second electrode, each of the first electrode and the second electrode forms capacitance with the facing detection electrode based on the reference potential or the drive signal, and the detection electrodes form capacitances with the first electrode and the second electrode of the input support device and the adjacent drive electrode and output the detection signals that are generated based on the capacitances to the control circuit, and
- the control circuit forms two-dimensional distribution of a plurality of signal values corresponding to the detection region based on the detection signals that are output from the detection electrodes and detects, from the two-dimensional distribution, a plurality of positive-polarity regions formed by a plurality of positive-polarity signal values of equal to or larger than a predetermined first threshold and a plurality of negative-polarity regions formed by a plurality of negative-polarity signal values of equal to or smaller than a predetermined second threshold.
2. The input detection system according to claim 1, wherein the control circuit detects a position of the input support device in the detection region and an orientation of the input support device based on the positive-polarity regions and the negative-polarity regions in the two-dimensional distribution.
3. The input detection system according to claim 1, wherein the control circuit calculates, as an electrode angle, an angle formed by a virtual line connecting the two positive-polarity regions adjacent to each other among the positive-polarity regions and a first direction as a direction in which the drive electrodes are aligned.
4. The input detection system according to claim 1, wherein
- the control circuit detects a first positive-polarity region, a second positive-polarity region, and a third positive-polarity region from the two-dimensional distribution and calculates a first electrode angle formed by a virtual line connecting the first positive-polarity region and the second positive-polarity region adjacent to each other and a first direction as a direction in which the drive electrodes are aligned, and
- the control circuit calculates a second electrode angle formed by a virtual line connecting the first positive-polarity region and the third positive-polarity region adjacent to each other and the first direction.
5. The input detection system according to claim 4, wherein
- the control circuit further multiplies each of the first electrode angle and the second electrode angle by a ratio of a maximum signal value of the second positive-polarity region to a maximum signal value of the third positive-polarity region as a coefficient, thereby correcting the first electrode angle and the second electrode angle, and
- the control circuit further calculates a final electrode angle using the corrected first electrode angle and the corrected second electrode angle.
6. The input detection system according to claim 1, wherein
- the control circuit detects a first positive-polarity region, a second positive-polarity region, and a third positive-polarity region from the two-dimensional distribution and calculates a position of an intermediate positive-polarity region between the second positive-polarity region and the third positive-polarity region based on a ratio of a maximum signal value of the second positive-polarity region to a maximum signal value of the third positive-polarity region, and
- the control circuit calculates, as an electrode angle, an angle formed by a virtual line connecting two of the first positive-polarity region and the intermediate positive-polarity region adjacent to each other and a first direction as a direction in which the drive electrodes are aligned.
7. The input detection system according to claim 4, wherein the first positive-polarity region includes a maximum signal value in the two-dimensional distribution of the signal values in detection of the electrode angle.
8. The input detection system according to claim 3, wherein
- the input support device holds the first electrode and the second electrode in a rotatable manner around a rotating axis, and
- the control circuit applies the calculated electrode angle to a conversion table indicating a relation between the electrode angle and rotation angles of the first electrode and the second electrode to calculate a rotation angle of the input support device.
9. The input detection system according to claim 8, wherein the first electrode faces the second electrode with respect to the rotating axis.
10. The input detection system according to claim 4, wherein
- the input support device holds the first electrode and the second electrode in a rotatable manner around a rotating axis, and
- the control circuit applies the calculated electrode angle to a conversion table indicating a relation between the electrode angle and rotation angles of the first electrode and the second electrode to calculate a rotation angle of the input support device.
11. The input detection system according to claim 10, wherein the first electrode faces the second electrode with respect to the rotating axis.
12. The input detection system according to claim 6, wherein
- the input support device holds the first electrode and the second electrode in a rotatable manner around a rotating axis, and
- the control circuit applies the calculated electrode angle to a conversion table indicating a relation between the electrode angle and rotation angles of the first electrode and the second electrode to calculate a rotation angle of the input support device.
13. The input detection system according to claim 12, wherein the first electrode faces the second electrode with respect to the rotating axis.
14. The input detection system according to claim 1, wherein an area of the first electrode is different from an area of the second electrode in a plan view.
15. The input detection system according to claim 14, wherein the area of the second electrode is larger than the area of the first electrode.
16. The input detection system according to claim 15, wherein the first electrode overlaps with at least equal to or more than one drive electrode, and the second electrode overlaps with at least equal to or more than two drive electrodes.
17. The input detection system according to claim 15, wherein the first electrode overlaps with at least equal to or more than one detection electrode, and the second electrode overlaps with at least equal to or more than two detection electrodes.
Type: Application
Filed: Jan 13, 2022
Publication Date: Jul 21, 2022
Patent Grant number: 11513639
Inventors: Takaaki KONO (Tokyo), Yuto KAKINOKI (Tokyo), Makoto HAYASHI (Tokyo)
Application Number: 17/574,903